BERLIN, April 23 (Reuters) - Bayern Munich, with one trophy in the bag and a second almost sewn up, turn their attentions to a possible treble when they face Zenit St Petersburg in Thursday's UEFA Cup semi-finals. Having won the German Cup on Saturday and holding a 10-point Bundesliga lead with five matches remaining, the 1996 UEFA Cup winners are favourites to go through to the May 14 final in Manchester against Fiorentina or Rangers. Champions Zenit are struggling at the start of the new Russian season, lying 10th in the league with one win and seven points from six matches. Bayern, who made winning the treble their aim after failing to qualify for the Champions League for the first time in a decade, will be without suspended top scorer Luca Toni for the first leg in the Allianz Arena. The Italy striker, who has scored eight goals in four games, was booked in the thrilling 3-3 quarter-final draw at Getafe when he netted twice in the final five minutes of extra-time to put Bayern through on away goals. 'We won the Cup and now we want the league championship and the UEFA Cup for the treble,' Toni told reporters after scoring twice in Saturday's 2-1 victory over Borussia Dortmund, his 34th and 35th goals of the season. 'We've still got two titles to go. I hope by the end of May we'll have all three.' Zenit crushed Bayer Leverkusen in the quarter-finals, winning 4-1 in Germany before losing the return leg 1-0. Ukraine midfielder Anatoliy Tymoschuk, who sat out Saturday's 1-1 draw against Saturn, is expected to return to coach Dick Advocaat's team. 'We can't let up now,' Bayern captain Oliver Kahn said. 'It's always difficult when you're in several competitions at the same time. 'It might not always look so elegant but what's important is the result.' One Bayern player who will not look elegant is midfielder Mark van Bommel. He broke his nose in the German Cup final after colliding with Dortmund's Mladen Petric and refused to comply with doctor's orders for an immediate operation. 'We've reached the critical moment in the season with the UEFA Cup semi-final,' said van Bommel. 'I've got to play. Having a crooked nose for a few weeks isn't so bad.'